Exercise: Use the Validating event to check inputs

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This exercise asks you to validate form input. First add the existing form called frmNewHeart from the folder shown above into your project:

Call the ValidateChildren method when you click on the Apply button, but don't do anything else yet at this stage

Now attach code to the Validating event of the txtName textbox, to display a message if it has been left blank:

What your MessageBox could show

Do the same thing for the txtAge field, but for this check also that the age entered is a whole number:

You could use a try / catch clause or the TryParse method to do this

Everyone lies about their age: add code to the txtAge textbox's Validated event to increase the age after it has passed validation: